Neoplasia at 10-year follow-up screening colonoscopy in a private U.S. practice: comparison of yield to first-time examinations

Abstract

Background and Aims Prior studies assessing the yield of a second screening colonoscopy performed 10 years after an initial negative screening colonoscopy did not include a control group of persons undergoing their first screening colonoscopy during the same time interval. Our aim was to describe the incidence of neoplasia at a second screening colonoscopy (performed at least 8 years after the first colonoscopy) in average risk individuals and compare it with the yield of first screening examinations performed during the same time interval. Methods Review of a database of outpatient screening colonoscopies performed between January 2010 and December 2015 in an Atlanta private practice. Results A total of 2105 average risk individuals underwent screening colonoscopy, including 470 individuals (53.6% female; mean age 64.0 ± 3.9 years) who underwent a second screening examination. In those undergoing second screening, the mean interval between examinations was 10.4 years (±1.1; range 8-15 years). At second screening, the polyp detection rate (PDR), adenoma detection rate (ADR) and advanced neoplasm rate (ANR) were 44.7%, 26.6%, and 7.4%, respectively. Of 40 advanced neoplasms in 35 individuals, 33 (82.5%) were proximal to the sigmoid colon, and there were no cancers. During the same interval, 1635 individuals (49.4% female; mean age 52.6 ± 3.4 years) underwent their first screening colonoscopy. The PDR, ADR and ANR were 53.5%, 32.2%, and 11.7%, respectively. Of 243 advanced neoplasms in 192 individuals, 152 (62.6%) were proximal to the sigmoid colon, and there were no cancers. After adjustment for age, gender, body mass index, and endoscopist, PDR, ADR, and ANR were all lower at the second screening colonoscopies than at first-time colonoscopies (all p<0.001). Conclusions Despite being 10 years older, persons with a negative screening colonoscopy 10 years earlier had numerically lower rates of adenomas and advanced neoplasms at their second screening examination compared with patients in the same practice undergoing their first screening colonoscopy, and they had no cancers. The fraction of advanced neoplasms that were proximal to the sigmoid was high in both first and second screenings. These results support the safety of the recommended 10-year interval between colonoscopies in average risk persons with an initial negative examination.